My schedule is quite flexible - I could arrange to meet with you any day next week.

flexible 是形容词，由词根 flex（弯曲、灵活）和后缀 -ible（能够...的）组成，字面意思是"能够弯曲的"，引申为"灵活的、可变通的"。在这里指日程安排可以调整变动。